Manufacturing method of hydrogen and synthesis gas

ABSTRACT

This invention provides a catalyst for producing hydrogen gas from a mixed gas comprising dimethyl ether and water vapor or carbon dioxide gas, which comprises copper, iron, cobalt, palladium, iridium, platinum, rhodium, or nickel as an active component, and a method of producing synthesis gas or hydrogen gas in a high yield at a low temperature. By using the catalyst, fuel cell, electricity generation, reduction of iron ore and the like can be carried out.

TECHNICAL FIELD

[0001] The invention relates to a catalyst for producing hydrogen orsynthesis gas from a mixed gas containing dimethyl ether and water vaporor carbon dioxide, and a manufacturing method of hydrogen or synthesisgas using the same.

BACKGROUND ART

[0002] Synthesis gas is composed of carbon monoxide and hydrogen, andhas wide applications as a raw material for ammonia synthesis andvarious chemical products, as well as used directly as a raw materialfor methanol synthesis, oxo synthesis, Fischer-Tropsch synthesis and thelike.

[0003] Heretofore, some methods of manufacturing synthesis gas andmethods of manufacturing hydrogen utilizing them are known.

[0004] For example, there are (1) gasification of coal, (2) steamreforming of hydrocarbon using natural gas, LPG, naphtha or the like asthe raw material, (3) partial oxidation of hydrocarbon using naturalgas, LPG, naphtha, heavy-duty oil or the like as the raw material, andso on.

[0005] However, the above coal gasification of (1) has a problem that avery complex and expensive coal gasification oven is necessary, and theapparatus becomes a large scale plant. The steam reforming ofhydrocarbon of (2) has a problem that a special reforming oven isnecessary because of requiring a high temperature of 700 to 1200° C. forreaction proceeding due to its great endothermic reaction, and thecatalyst to be used is required to have a high heat resistance. Thepartial oxidation of hydrocarbon of (3) has a problem that a specialpartial oxidation oven is necessary because of requiring a hightemperature of 1200 to 1500° C., the treatment of a large quantity ofsoot generated with reaction proceeding is a problem, and in the case ofusing a catalyst, the catalyst is deteriorated by the deposition of alarge quantity of carbonaceous material on the surface of the catalyst.

[0006] An object of the invention is to provide a catalyst and amanufacturing method capable of solving the problems of the above priorart, and obtaining hydrogen or synthesis gas in a high yield at a lowtemperature.

DISCLOSURE OF INVENTION

[0007] The inventors investigated eagerly in order to solve the aboveproblems, and as a result, they noted dimethyl ether as the raw materialgas. Then, they found that copper, iron, cobalt, palladium, iridium,platinum, rhodium and nickel are very effective as a catalyst forreacting dimethyl ether with water vapor or carbon dioxide to producehydrogen or synthesis gas, and can produce hydrogen or syntheses gasefficiently at a low temperature to complete the invention.

[0008] Thus, the invention relates to a catalyst for producing hydrogengas from a mixed gas comprising dimethyl ether and water vapor or carbondioxide gas, which comprises copper, iron, cobalt, palladium, iridium,,platinum, rhodium, or nickel as an active component, and a method ofproducing hydrogen or synthesis gas which comprises contacting a mixedgas comprising dimethyl ether and water vapor or carbon dioxide gas withthe above catalyst.

BRIEF DESCRIPTION OF DRAWINGS

[0009]FIG. 1 illustrates a constitution of a fuel cell provided with areformer using the catalyst of the invention.

[0010]FIG. 2 illustrates a constitution of a solid electrolyte-type fuelcell using dimethyl ether or hydrogen.

[0011]FIG. 3 shows electricity generation characteristics of the solidelectrolyte-type fuel cell using dimethyl ether or hydrogen.

[0012]FIG. 4 is a flow sheet illustrating an engine electricitygeneration system using hydrogen or synthesis gas obtained by using thecatalyst of the invention.

[0013]FIG. 5 is a flow sheet illustrating a general constitution of ironore reducing system using hydrogen or synthesis gas obtained by usingthe catalyst of the invention.  1 Fuel cell  2 Solid electrolyte-typefuel cell  3 Air supply line  4 Dimethyl ether supply line  5 Watervapor supply line  6 Reformer (reforming reactor) 11 Sintering machineexhaust gas cooler 12, 13, 14 Heat exchanger 15 Reformer 16 Combustor 17Compressor 18 Gas turbine 19 Electricity generator 20 Heat recoveringboiler 21 Heat exchanger 22 Blower 23 Reformer 24 Heating furnace 25Iron ore reducing furnace

BEST MODE FOR CARRYING OUT THE INVENTION

[0014] The catalyst of the invention is able to produce hydrogen gasfrom a mixed gas comprising dimethyl ether and water vapor or carbondioxide, and comprises copper, iron, cobalt, palladium, iridium,platinum, rhodium or nickel as an active component.

[0015] Among the active components, cobalt, palladium, iridium,platinum, rhodium and nickel produce synthesis gas from dimethyl etherand water vapor, and copper, cobalt and palladium produce synthesis gasfrom dimethyl ether and carbon dioxide. That is, cobalt and palladiumcan produce synthesis gas from both of water vapor and carbon dioxide.On the other hand, copper and iron produce mainly hydrogen when usingwater vapor.

[0016] The active component is incorporated in the catalyst in a form ofmetal or compound. Preferable copper compounds are copper oxides, andthe copper oxides are cuprous oxide (Cu₂O, cupric oxide (CuO) and theirmixtures. Preferable iron compounds are iron oxides, and the iron oxidesare ferrous oxide (FeO), ferric oxide (Fe₂O₃) and their mixtures.Preferable cobalt compounds are cobalt oxides, and the cobalt oxides arecobaltous oxide (CoO), cobaltic oxide (Co₂O₃) and their mixtures.Preferable palladium compounds are palladium oxides and chlorides, thepalladium oxides are palladous oxide (PdO), palladium sesquioxide(Pd₂O₃), palladic oxide (PdO₂), and their mixtures, and the palladiumchlorides are palladium dichloride (PdCl₂), palladium tetrachloride(PdCl₄) and their mixtures. Preferable iridium compounds are iridiumoxide and chloride, the iridium oxide is IrO₂, and the iridium chlorideis IrCl₃. Preferable platinum compounds are platinum oxides andchlorides. The platinum oxides are PtO and PtO₂, and the platinumchlorides are PtCl₂, PtCl₃ and PtCl₄. Preferable rhodium compounds arerhodium oxide and chloride. The rhodium oxide is Rh₂O₃, and the chlorideis RhCl₃ Preferable nickel compounds are nickel sulfides, and the nickelsulfides are NiS, Ni₃S₂ or their mixtures.

[0017] The catalyst of the invention may be carried by a catalystcarrier. Preferable catalyst carriers are oxides, such as alumina,silica gel, silica alumina, zeolite, titania, zirconia, zinc oxide, tinoxide, lanthanum oxide and cerium oxide, and particualrly, alumina isprefearble because of high synthesis gas yield. The content in thecatalyst is, in the case of copper, about 1 to 50 wt. %, preferablyabout 3 to 30 wt. %, in the case of iron, about 10 to 100 wt. %,preferably about 30 to 100 wt. %, in the case of cobalt, about 1 to 30wt. %, prefearbly about 3 to 15 wt. %, in the case of iridium, platinumand rhodium, about 0.05 to 10 wt. %, prefeably about 0.1 to 5 wt. %, andin the case of nickel, about 0.5 to 30 wt. %, preferably about 1 to 15wt. %. When the content is out of the above range, the yield of hydrogenand synthesis gas is degraded.

[0018] The catalyst of the invention may be combined with other metalsor compounds than the above metals or their compounds. Examples of theother metals and compounds are, in the case of copper catalyst, zinc,chromium, nickel, manganese, tin, cerium, lanthanum and their compounds.The content of the above third component is 70 wt. % or less,particularly 50 wt. % or less, and in the case of incorporating, ingeneral, about 1 to 30 wt. %.

[0019] In the case of iron catalyst, examples of the other metals andcompounds are zinc, nickel, chromium, manganese, tin, cerium, lanthanumand their compounds. Among them, oxides of zinc, nickel, chromium andmanganese are preferred. The content of the above third component is 50wt. % or less, particularly 30 wt. % or less, and in the case ofincorporating, in general, about 1 to 20 wt. %. In the case of cobaltcatalyst, examples of the other metals and compounds are metals ofnickel and iron and their compounds. The content of the above thirdcomponent is 20 wt. % or less, particularly 10 wt. % or less, and in thecase of incorporating, in general, about 1 to 5 wt. %.

[0020] In the case of iridium catalyst, platinum catalyst and rhodiumcatalyst, examples of the other metals and compounds are metals ofcopper, cobalt, nickel and iron and their compounds. The content of theabove third component is 20 wt. % or less, particularly 10 wt. % orless, and in the case of incorporating, in general, about 1 to 5 wt. %.

[0021] In the case of nickel catalyst, examples of the other metals andcompounds are metals and/or compounds of copper, cobalt and iron. Thecontent of the above third component is 20 wt. % or less, particularly10 wt. % or less, and in the case of incorporating, in general, about 1to 5 wt. %.

[0022] The above third components may be incorporated as a singlematerial, or two or more types thereof may be mixed and incorporated.

[0023] It is preferable that the palladium catalyst is carried by ametal oxide having basicity. The metal oxide having basicity is alkalimetal oxide, such as Li₂O, Na₂O, K₂O, Rb₂O or Cs₂O, alkaline earth metaloxide, such as BeO, MgO, CaO, SrO or BaO, rare earth element oxide, suchas Y₂O₃, La₂O₃ or CeO₂, ZnO, SnO₂, ZrO₂, Al₂O₃, TiO₂ and a mixture oftwo or more of the above metal oxides. The metal oxide having basicitymay be combined with another metal oxide not having basicity, such assilica gel, or another compound not having basicity, such as siliconcarbide or activated carbon. The carrying rate of palladium is about 0.1to 30 wt. %, preferably 0.2 to 20 wt. % of the metal oxide havingbasicity. When the carrying rate of palladium is less than about 0.1 wt.% or more than about 30 wt. %, the yield of synthesis gas is degraded.

[0024] By using the metal oxide having basicity as the carrier ofpalladium which is an active component, synthesis gas can be produced ina high yield with restraining the production of hydrocarbons mainlymethane.

[0025] It is also effective to combine a solid acidic compound with thepalladium-carried metal oxide, and by using the catalyst, synthesis gascan be produced from dimethyl ether and water vapor. The catalyst ismade by mixing physically palladium carried by the metal oxide and acompound having solid acidity.

[0026] The metal oxide used for carrying palladium is silica gel,titania, alumina, silica-alumina, zirconia, tin oxide, zinc oxide or thelike, and particularly, silica gel and titania are preferable because ofhigh synthesis gas yield. The palladium carried by the metal oxide isabout 0.05 to 30 wt. %, preferably about 0.1 to 20 wt. % of the metaloxide. When the carrying rate of palladium is less than about 0.05 wt. %or more than about 30 wt. %, the yield of synthesis gas is degraded. Toone side of the catalyst components constituting the catalyst of theinvention, other metal(s) than palladium or compound(s) thereof can becombined. Examples of the other metal(s) and compound(s) are alkalimetal oxides, such as Li₂O, Na₂O, K₂O, Rb₂O and Cs₂O, alkaline earthmetal oxides, such as BeO, MgO, CaO, SrO and BaO, rare earth elementoxides, such as Y₂O₃, La₂O₃ and CeO₂, and mixtures of two or more of theabove metal oxides. The content of the above third component is 20 wt. %or less, particularly 10 wt. % or less, and in the case ofincorporating, in general, about 1 to 5 wt. %.

[0027] The compounds having solid acidity are alumina, silica-alumina,silica-titania, zeolite, aluminum phosphate and the like, and alumina isparticularly preferred because of high synthesis gas yield.

[0028] In the catalysis, by the catalytic action of the compound havingsolid acidity, dimethyl ether is hydrolyzed to produce metahnol (formula(1)), and subsequently, produced methanol is contacted withpalladium-carried metal oxide catalyst to produce synthesis gas bydecomposing the methanol (formula(2)). By mixing the above two types ofcatalysts physically, synthesis gas can be obtained in a high yield.

CH₃OCH₃+H₂O→2CH₃OH  (1)

CH₃OH→CO+2H₂  (2)

[0029] To the production of the above respective catalysts, generalpreparations of these type catalysts can be applied. For example, aninorganic acid salt, such as nitrate, carbonate or halide, or an organicacid salt, such as acetate or oxalate, as the compound of the catalyticactivity component metal can be used as the raw material for producingthe catalyst. For the carrying operation of the active component ontothe catalyst carrier, usual techniques, such as precipitation, kneading,impregnation and ion-exchange method, can be utilized. The catalystcomposition thus produced is optionally sintered by a conventionalmethod. The sintering is preferably conducted by heating at 300 to 800°C. for 1 to 10 hours in nitrogen or air atmosphere.

[0030] Moreover, the catalyst is preferably activated before subjectedto the reaction, and in the case of metal catalyst, it is preferable totreat at 300 to 600° C. for 1 to 10 hours in a hydrogen atmosphere. Onthe other hand, the previous activation treatment is not necessary foroxide catalysts. In the case of sulfides, it is preferable to treat at300 to 600° C. for 1 to 10 hours in a hydrogen atmosphere containing 1to 50% of hydrogen sulfide (H₂S), dimethyl sulfide (CH₃SCH₃) or dimethyldisulfide (CH₃SSCH₃).

[0031] Upon making nickel into a sulfide, the sulfidation, may becarried out according to a conventional method, and it is preferable toheat at 300 to 600° C. for 1 to 10 hours in an atmosphere of one ofhydrogen sulfide, dimethyl sulfide, dimethyl disulfide or carbondisulfide or a mixed gas of two or more of them or a mixed gas of theabove and hydrogen. A suitable mixing ratio of hydrogen and the abovesulfur compound is about 1:0.05 to 1:1.

[0032] Upon manufacturing a catalyst of palladium carried by a metaloxide having basicity, the basicity of the metal oxide having basicityis lost by contacted with a strongly acidic aqueous solution containingpalladium. Thereupon, the manufacturing of the catalyst is characterizedby treating with a basic aueous solution, after palladium is carried bythe metal oxide, in order to recover the basicity of the metal oxide. Bythis treatment, synthesis gas can be obtained in a high yield. That is,it is characterized that, after palladium is carried by the metal oxidehaving basicity, it is treated with a basic aqueous solution. As themanufacture of the catalyst, a metal oxide having basicity is added toan aqueous solution containing a metal salt of palladium, such aspalladium chloride, evaporated to dryness, dried, followed by sintering.The sintering is preferably carried out by heating at 350 to 600° C. for1 to 10 hours in nitrogen or air. Subsequently, this matter is teatedwith basic aqueous solution. As the basic aqueous solution, aqueoussolutions of hydroxide or carbonate of alkali metal and hydroxide ofalkaline earth metal can be listed. A suitable concentration the basiccompound is about 0.5 to 20, usually about 1 to 10. The treatment iscarried out by contacting the catalyst with the basic aqueous solution,followed by removing the basic aqueous solution. This treatment ispreferably carried out at ordinary temperature to 80° C. for 1 to 5hours. Besides, it is possible that, after treated with basic aqueoussolution, for example, a small amount (e.g. about 0.1-1.0) of the abovebasic compound is carried. The catalyst is activated in the final stageof preparation, and the activation is preferably carried out by treatingat 350 to 600° C. for 1 to 10 hours in a hydrogen atmosphere.

[0033] To the production of the palladium-carried metal oxide catalystin the catalyst containing the palladium-carried metal oxide and thesolid acidic compound, general preparations of this type catalyst can beapplied. For example, an inorganic acid salt, such as nitrate, carbonateor halide, or an organic acid salt, such as palladium acetate orpalladium oxalate, can be used as the palladium compound of the rawmaterial for producing the catalyst. For the carrying operation ofpalladium onto the metal oxide carrier, usual techniques, such asprecipitation, kneading, impregnation and ion-exchange method, can beutilized. The catalyst composition thus produced is optionally sinteredby a conventional method. The sintering is preferably conducted byheating at 300 to 600° C. for 1 to 10 hours in nitrogen or airatmosphere. Subsequently, the catalyst composition is preferably treatedat 300 to 600° C. for 1 to 10 hours in a hydrogen atmosphere.

[0034] As to the mixing of the palladium-carried metal oxide and thesolid acidic compound, either way may be taken, i.e. both components arepelletized and then mixed with each other physically, or both componentsare pulverized, mixed physically and then, pelletized by compressionmolding. The mixing ratio of both components is not especially limited,but selected according to the type of each component, reactionconditions and the like. In usual, the ratio is about 1:10 to 10:1,preferably about 1:5 to 5:1, as a weight ratio.

[0035] Hydrogen or synthesis gas can be obtained in a high yield bystreaming a mixed gas of dimethyl ether and water vapor or carbondioxide through each of the above catalyst thus prepared.

[0036] In the invention, water vapor of carbon dioxide is suppliedtogether with dimethyl ether which is the raw material. The supplyamount, in the case of water vapor, is enough to the theoretical amountor more, and in the case of producing synthesis gas, the supply amountis 1 to 20 times, preferably 1 to 10 times, molar quantity. On the otherhand, in the case of producing hydrogen, the supplied amount is 1 to 30times, preferably 1 to 20 times, molar quantity. When the supply ofwater vapor is less than one time molar quantity, high dimethyl etherconversion rate cannot be obtained. The supply exceeding 20 times or 30times is uneconomical. On the other hand, the supply amount, in the caseof carbon dioxide, is 0.8 to 2.0 times, preferably 0.9 to 1.5 times, themolar quantity of dimethyl ether which is the raw material. When thesupply of carbon dioxide is less than 0.8 time molar quantity, highdimethyl ether conversion rate cannot be obtained. Exceeding 20 timesmolar quantity is also undersirable because of the necessity of removingcarbon dioxide which remains abundanty in the produced gas. It is amatter of course that carbon dioxide is combined with water vapor. Theraw material gas can contain other component(s) than dimethyl ether andwater vapor or carbon dioxide. In the case of using carbon dioxide, themolar ratio of H₂ is raised by adding water vapor as the othercomponent.

[0037] Particularly, in the case of the catalyst using cobalt as anactive component and of the catalyst of palladium carried by a metaloxide having basicity, water vapor and/or carbon dioxide is suppliedtogether with dimethyl ether which is the raw material. The supplyamount in the case of supplying one of water vapor or carbon dioxide isthe same as above. On the other hand, in the case of supplying bothwater vapor and carbon dioxide, the total of water vapor and carbondioxide is 1 to 10 times, preferably 1 to 5 times, the molar quantity ofdimethyl ether. When the total of water vapor and carbon dioxide is lessthan one time, high dimethyl ether conversion rate cannot be obtained.Exceeding 10 times molar quantity is also undesirable because ofuneconomy and the necessity of removing carbon dioxide.

[0038] The raw material gas may contain other component(s) than dimethylether and water vapor, carbon dioxide. It can contain inactive gas tothe reaction, such as nitrogen, inert gas, CO, H₂ or methane as theother component (s). A suitable content of them is 30 vol. % or less,and exceeding the range induces a problem of decreasing reaction rate.It is desirable to remove air (oxygen) as much as possible because ofburning dimethyl ether, and an allowable content is 5% or less as air.

[0039] The reaction temperature is, in the case of supplying dimethylether and water vapor to produce synthesis gas, 200° C. or more,preferably 250° C. or more, particularly preferably 300° C. or more, and600° C. or less, preferably 500° C. or less, more preferably 450° C. orless, particularly preferably 400° C. or less. In the case of supplyingdimethyl other and carbon dioxide to produce synthesis gas, the reactiontemperatures is 200° C. or more, preferably 250° C. or more,particularly preferably 300° C. or more, and 600° C. or less, preferably500° C. or less, particularly preferably 450° C. or less. In the case ofsupplying dimethyl ether and water vapor to produce hydrogen, thereaction temperature is 150° C. or more, preferably 200° C. or more,particularly preferably 250° C. or more, and 500° C. or less, preferably450° C. or less, particularly preferably 400° C. or less. The catalystcontaining copper, platinum or palladium as an active component has agreat low temperature activity. In the lower reaction temperature thanthe above range, high dimethyl ether conversion rate cannot be obtained,and the production rate of carbon dioxide increases to decrease theyield of hydrogen and synthesis gas. In the higher reaction temperaturethan the above range, in the case of producing synthesis gas, theproduction of hydrocarbons, mainly methane, is remarkable, and the rateof hydrogen and synthesis gas in the product is decreased, andtherefore, undesirable. In the case of producing hydrogen gas, the rateof produced methanol and carbon monoxide as by-products increases in thereaction temperature higher than the above range to decrease the yieldof hydrogen. Particularly, in the case of copper catalyst, grain growthof copper which is the active component is remarkable to decreasecatalystic activity gradually, and therefore, undesirable.

[0040] The reaction pressure is preferably ordinary pressure to 10kg/cm². When the reaction pressure exceeds 10 kg/cm², the conversionrate of dimethyl ether decreases.

[0041] A preferable space velocity (supply velocity m³/h of the mixedgas in the standard conditions per 1 m³ catalyst) is, in the case of theproduction of synthesis gas, 1,000 to 20,000 m³/m³·h, in the case of theproduction of hydrogen, 1,000 to 50,000 m³/m³·h, particularly 30,000m³/m³·h or less. When the space velocity is greater than the aboverange, the conversion rate of dimethyl ether decreases. On the otherhand, the space velocity of smaller than the above range isuneconomical, because the size of a reactor is very large.

[0042] In the method of the invention, the apparatus may be either afixed bed or a fluidized bed.

[0043] In the case of producing synthesis gas by using the catalyst ofthe invention, as to the cobalt catalyst, the conversion rate ofdimethyl ether is about 70 to 100%, usually about 80 to 100%, andsynthesis gas can be obtained in a yield of about 70 to 100%, usuallyabout 80 to 95%. The H₂/CO ratio of the produced synthesis gas is about0.5 to 4, usually about 0.6 to 3 as molar ratio. As to by-products,methanol is 2 or less, usually 1 or less, and hydrocarbons are 20 orless, usually 10 or less.

[0044] As to the palladium-carried basic metal oxide catalyst, theconversion rate of dimethyl ether is about 60 to 100%, usually about 80to 100%, and synthesis gas can be obtained in a yield of about 60 to100%, usually about 80 to 100%. As to by-products, methanol is 1.0 orless, usually 0.5 or less, and hydrocarbons are 10 or less, usually 5 orless.

[0045] As to the iridium catalyst, the conversion rate of dimethyl etheris about 60 to 100%, usually about 70 to 100%, and synthesis gas can beobtained in a yield of about 60 to 95%, usually about 70 to 95%. As toby-products, methanol is 10% or less, usually 5% or less, andhydrocarbons are 20% or less, usually 10% or less.

[0046] As to the platinum catalyst, the conversion rate of dimethylether is about 60 to 100%, usually about 70 to 100%, and synthesis gascan be obtained in a yield of about 50 to 90%, usually about 60 to 80%.As to by-products, methanol is 20% or less, usually 10% or less, andhydrocarbons are 5% or less, usually 5 or less.

[0047] As to the rhodium catalyst, the conversion rate of dimethyl etheris about 50 to 100%, usually about 60 to 90%, and synthesis gas can beobtained in a yield of about 50 to 90%, usually about 60 to 80%. As toby-products, methanol is 10% or less, usually 5% or less, andhydrocarbons are 20% or less, usually 10% or less.

[0048] As to the catalyst composed of palladium-carried metal oxide andsolid acidic compound, the conversion rate of dimethyl ether is about 50to 100%, usually about 60 to 100%, and synthesis gas can be obtained ina yield of about 40 to 90%, usually about 50 to 90%. As to by-products,methanol is 20% or less, usually 5% or less, and hydrocarbons are 20% orless, usually 5% or less.

[0049] As to the nickel catalyst, the conversion rate of dimethyl etheris about 60 to 95%, usually about 70 to 90%, and synthesis gas can beobtained in a yield of about 50 to 95%, usually about 40 to 90%. As toby-products, methanol is 10% or less, usually 5% or less, andhydrocarbons are 20% or less, usually 5% or less.

[0050] As to the copper catalyst using carbon dioxide, the conversionrate of dimethyl ether is about 50 to 100%, usually about 70 to 95%, andsynthesis gas can be obtained in a yield of about 50 to 100%, usuallyabout 70 to 95%. The H₂/CO ratio of the produced synthesis gas is about0.6 to 1.3, usually about 0.8 to 1.1 as molar ratio. As to by-products,hydrocarbons are 5% or less, usually 2% or less.

[0051] In the case of producing hydrogen, as to the copper catalyst, theconversion rate of dimethyl ether is about 60 to 100%, usually about 80to 100%, and hydrogen can be obtained in a yield of about 55 to 100%,usually about 80 to 95%. As to by-products, methanol is 10 or less,usually 5 or less, hydrocarbons are 0.5 or less, usually 0.3 or less,and carbon monoxide is 10 or less, usually 5 or less.

[0052] As to the iron catalyst, the conversion rate of dimethyl ether isabout 80 to 100%, usually about 90 to 100%, and hydrogen can be obtainedin a yield of about 70 to 100%, usually about 80 to 100%. As toby-products, methanol is 0.5 or less, usually 0.3 or less, hydrocarbonsare 5 or less, usually 2 or less, and carbon monoxide is 10 or less,usually 5 or less.

[0053] The hydrogen and synthesis gas produced from dimethyl ether usingthe catalyst of the invention can be used for fuel cell.

[0054] Recently, electricity generation by fuel cell has been noted,because of less environmental pollution, less noise, less energy lossand advantages in setting and operation.

[0055] Since fuel cell is, in principle, an energy converter convertingchemical energy of hydrogen which is fuel gas directly to electricenergy, a stable supply in large quantity of hydrogen is necessary. Thesupply in large quantity of hydrogen is carried out using city gascontaining hydrocarbons, such as methane or natural gas, propane, butaneor petroleum gas, naphtha, kerosene, gas oil or synthetic petroleum oilor hydrogen, as a principal component, or methanol, as the raw materialfuel, and reforming them to hydrogen and carbon dioxide gas or carbonmonoxide by a reformer, as described in Japanese Patent KOKAI 7-48101.

[0056] In the case of using the raw material fuel for a portableelectric source of an electric car or fuel cell for electricitygeneration plant located at a far place where city gas cannot beutilized, preferable raw material fuels are liquids and easilyliquefiable materials, such as propane, butane, naphtha, kerozene, gasoil, synthetic petroleum oil and methanol, in terms of transportation,storage place, safty and the like. However, in the case of using aheavy-duty hydrocarbon, such as propane, butane, naphtha, kerosene, gasoil or synthetic petroleum oil, there is a problem of decreasingreforming efficiency due to the deposition of carbon on the catalystsurface during reforming, unless setting of reformer conditions iscarefully controlled. Methanol containing oxygen has no problem ofcarbon deposition, but corrosion of reformer is a problem because ofproducing formic acid exhibiting strong corrosive action in thereforming process.

[0057] On the other hand, a national project is being scheduled, whereindimethyl ether which is clean, not containing ashes and sulfur, andexcellent in handling is mass-produced cheaply from poor grade coals,and utilized for fuel. Dimethyl ether is expected to be utilized for newapplications, such as fuel cell, in view of transportation, storageplace, safty and the like, and also in view of environmental protection,due to its easy liquefaction by pressuring at several atmosphericpressures.

[0058] Heretofore, to apply dimethyl ether to fuel cell has not beenreported yet.

[0059] The inventors investigated whether dimethyl ether can be reformedwithout a problem as fuel gas by a reformer for reforming conventionalraw material fuels for fuel cell to fuel gases or not.

[0060] A comparison of the composition of the reformed gas with naturalgas (methane) is shown in Table 1.

[0061] It can be seen that dimethyl ether can be reformed to hydrogen,carbon monoxide and water vapor even using a conventional reformer,similar to natural gas.

[0062] Accordingly, dimethyl ether can be utilized as a raw material forfuel cell without a problem. TABLE 1 Raw Material Fuel H₂O H₂ CO OthersDimethyl ether 27.3 47.6 12.6 12.5 Methane 29.2 51.1 9.1 10.6

[0063] In the case of solid electrolyte-type fuel cell, it is alreadyknown that the cost of solid electrolyte-type fuel cell is reduced bysupplying methane and water vapor as the fuel gas directly to a fuelelectrode (anode) to reform in the cell without passing a reformer, dueto its high operation temperature of about 1,000° C. However,electricity generation is also possible without a problem by supplying amixed gas containing dimethyl ether and water vapor directly as the fuelgas.

[0064] A constitution of a fuel cell provided with a reformer is shownin FIG. 1. In the figure, 1 is a fuel cell, 3 is an air supply line, 4is a dimethyl ether supply line, 5 is a water vapor supply line, and 6is a reformer, respectively.

[0065] Electricity generation can be conducted by using dimethyl etheras the raw material, supplying it to the reformer 6 together with watervapor to be reformed to hydrogen and carbon monoxide or carbon dioxide,and then, supplying it to the anode of the fuel cell land air which isthe oxidizing agent to the cathode of the fuel cell 1.

[0066] A constitution of a solid electrolyte-type fuel cell is shown inFIG. 2. In the figure, 2 is a solid electrolyte-type fuel cell.

[0067] When a mixed gas containing dimethyl ether and water vapor issupplied directly to the anode of the solid electrolyte-type fuel cell 2without passing a reformer, dimethyl ether 4 is reformed at the anode tohydrogen and carbon monoxide or carbon dioxide, etc. due to contactingan electrode material having catalytic action at a high temperature near1,000° C. Accordingly, electricity generation can be conducted bysupplying air which is the oxidizing agent to the cathode of the solidelectrolyte-type fuel cell 2.

[0068] It is no problem that the mixed gas containing dimethyl ether andwater vapor contains inactive gas, such as argon.

[0069] Electricity can be generated by reforming dimethyl ether usingthe catalyst of the invention to produce synthesis gas or hydrogen gas,and using the gas as the fuel for engine.

[0070] Heretofore, some methods of generating electricity using dimethylether are known.

[0071] For example, Japanese Patent KOKAI 2-9833 and 3-52835 discloseelectricity, generation methods of producing a combination of dimethylether and methanol from synthesis gas to store them, and using them inan integrated gasification complex cycle electricity generation plant atthe peak of natural gas electricity generation.

[0072] On the other hand, an electricity generation method usingmethanol reformed gas is known. The method is of obtaining the synthesisgas or hydrogen gas used as a fuel for electricity generation byreforming or cracking of methanol.

[0073] In the methanol reforming electricity generation method, a methodof carbureting (increasing heat) is also proposed by utilizing exhaustgas of turbines for electricity generation or combustion exhaust gas forthe reforming or cracking which is endothermic reaction. For example,Japanese Patent KOKAI 62-132701 discloses a heat recovering method whichutilizes the heat quantity of combustion exhaust gas for heating rawmaterials. The exhaust gas is of heat medium-heating furnace forsupplying heat necessary for reaction proceeding and heating rawmaterial gases to evaporate, in a methanol cracking apparatus forproducing synthesis gas from methanol and water.

[0074] However, in the electricity generation method disclosed inJapanese Patent KOKAI 2-9833 and 3-52835, there is no descriptionconcerning concrete electricity generation method at all.

[0075] Moreover, in the methanol reforming electricity generationmethod, the electricity generation efficiency is improved by carbureting(increasing heat) using waste heat of the exhaust gas of turbines forelectricity generation or combustion exhaust gas for reforming orcracking of raw material methanol. However, the heat quantityrecoverable through steam reforming of methanol and methanol cracking isnot so great as shown in the formulas (1) and (2), respectively.

CH₃OH+H₂O→CO₂+3H₂−11.8 kcal/mol  (1)

CH₃OH→CO+2H₂−21.7 kcal/mol  (2)

[0076] Besides, there are problems of careful handling and the like,because methanol has toxicity.

[0077] The inventors noted the method of obtaining synthesis gas orhydrogen gas by reforming dimethyl ether which has been developed by theinventors, and devised an electricity generation method using the gas asfuel for engine.

[0078] This method is an electricity generation method using dimethylether reformed gas which comprises reforming dimethyl ether to producesynthesis gas or hydrogen gas by adding water vapor or carbon dioxidegas to dimethyl ether followed by catalyzing, and using the gas as afuel for engine, and uses an electricity generation apparatus comprisinga reformer packed with a catalyst for reacting dimethyl ether with watervapor or carbon dioxide gas to produce synthesis gas or hydrogen gas, acombustor for burning the synthesis gas or hydrogen gas, and anelectricity generator having gas turbine rotating by the combustionexhaust gas generated in the combustor.

[0079] In the reforming reaction relating to the invention, heatquantity of endothermic reaction is great as shown in the formulas(3)-(5), and accordingly, it is possible to recover waste heat 1.5 to2.5 times as much as the conventional methanol reforming reaction, andheat quantity upon burning the reformed gas increases by the recoveredheat quantity.

CH₃OCH₃+H₂O→2CO+4H₂−48.9 kcal/mol  (3)

CH₃OCH₃+3H₂O→2CO₂+6H₂−29.3 kcal/mol  (4)

CH₃OCH₃+CO₂→3CO+3H₂−58.8 kcal/mol  (5)

[0080] For example, when 1 Nm³ dimethyl ether having a gross calorificvalue of 15,580 kcal/Nm³ is reformed by water vapor according to heformula (3), a synthesis gas consisting of 2 Nm³ carbon monoxide and 4Nm³ hydrogen is obtained. The gross calorific value of the synthesis gasis 18,240 kcal, and the increase of heat quantity is 2,660 kcal. Therate of heat quantity increase (the increase of heat quantity is dividedby the gross calorific value of dimethyl ether, and multiplied by 100)is calculated 17.1%. On the other hand, in the methanol reformingreaction, when 1 Nm³ methanol vapor having a gross calorific value of8,150 kcal/Nm³ is cracked, for example, according to the formula (2), asynthesis gas consisting of 1 Nm³ carbon monoxide and 2 Nm³ hydrogen isobtained. The gross calorific value of the synthesis gas is 9,120 kcal,and the increase of heat quantity is 970 kcal. The rate of heat quantityincrease (the increase of heat quantity is divided by the grosscalorific value of dimethyl ether, and multiplied by 100) is calculated11.9%.

[0081] Besides, dimethyl ether has already been utilized as a propellantfor spray, and confirmed that its toxicity is very small compared withmethanol.

[0082] In the method of the invention, it is preferable to give thereaction heat necessary for reforming dimethyl ether by the medium, lowtemperature waste heat at 200 to 500° C. generated in a ironmanufacturing factory or an electricity generation plant. For example,by using the sensible heat of the exhaust gas of a cooler generated in asintering factory of an iron manufacturing factory, or by utilizing theexhaust gas of gas turbines in an electricity generation plant, anincrease of the calorific value corresponding to the heat quantity ofthe reforming can be promised in the produced reformed gas. Furthermore,the reforming of dimethyl ether proceeds at a temperature of 200 to 500°C. by the presence of the above catalyst, and is suitable for therecovery of medium, low temperature waste heat.

[0083] The reformed gas of dimethyl ether is gaseous fuel comprisingmainly hydrogen or hydrogen and carbon monoxide, and is used as a fuelfor an engine for electricity generation, such as gas turbine. As themethod of combustion, the low temperature combustion, such as catalyticcombustion and dilute gas combustion, is also possible as well as normalcombustion, and in this case, the retardation of nitrogen oxidesgeneration can be expected.

[0084] The combustion conditions may be similar to the conventionalconditions using LNG or LPG.

[0085] Iron ore and recovered scrap iron can be reduced by usingsynthesis gas or hydrogen gas obtained by reforming dimethyl ether usingthe catalyst of the invention.

[0086] Heretofore, in the method of manufacturing reduced iron byreducing iron ore, some methods of producing synthesis gas or hydrogengas which is a reducing gas are known.

[0087] For example, there are (1) gasification of coal, (2) steamreforming of hydrocarbon using natural gas, LPG, naphtha or the like asthe raw material, (3) partial oxidation of hydrocarbon using naturalgas, LPG, naphtha, heavy-duty oil or the like as the raw material, andso on.

[0088] However, the above coal gasification of (1) has a problem that avery complex and expensive coal gasification oven is necessary, and theapparatus becomes a large scale plant. The steam reforming ofhydrocarbon of (2) has a problem that a special reforming oven isnecessary because of requiring a high temperature of 700 to 1200° C. forreaction proceeding due to its great endothermic reaction, and thecatalyst to be used is required to have a high heat resistance. Thepartial oxidation of hydrocarbon of (3) has a problem that a specialpartial oxidation oven is necessary because of requiring a hightemperature of 1200 to 1500° C., the treatment of a large quantity ofsoot generated with reaction proceeding is a problem, and in the case ofusing a catalyst, the catalyst is deteriorated by the deposition of alarge quantity of carbonaceous material on the surface of the catalyst.

[0089] The inventors devised a method of producing synthesis gas orhydrogen gas by reforming dimethyl ether using the catalyst of theinvention, and a method of reducing iron ore and recovered scrap ironusing the gas.

[0090] The above method includes a method of manufacturing reduced ironwhich comprises reforming dimethyl ether to produce synthesis gas orhydrogen gas by adding water vapor or carbon dioxide gas to dimethylether followed by catalyzing, and reducing iron ore or recovered scrapiron, a method of manufacturing reduced iron as described above whereinthe reforming of dimethyl ether is carried out using an exhaust gascontaining water vapor and carbon dioxide gas generated by reducing ironore or recovered scrap iron, and a method of manufacturing reduced ironas described above wherein the sensible heat of an exhaust gas generatedby reducing iron ore or recovered scrap iron for heating the reformingof dimethyl ether, and uses an apparatus for manufacturing reduced ironwhich comprises a reformer packed with a catalyst for reacting dimethylether with water vapor or carbon dioxide gas to produce synthesis gas orhydrogen gas, reducing furnace charged with iron ore or recovered scrapiron, wherein they are connected so as to supply the synthesis gas orhydrogen gas produced in the reformer to the reducing furnace.

[0091] As to the reducing furnace of iron ore or recovered scrap iron,the type is not especially limited, and any known type of shaft typefurnace, kiln type furnace, fluidized bed type furnace or rotary kilntype furnace is usable.

[0092] The reducing conditions may be similar to the conventionalmethod, at a temperature of about 800 to 1,000° C., at a pressure ofabout 1 to 10 atmospheric pressures, for a period of about 2 to 8 hours.

[0093] In the invention, it is preferable to use the water vapor andcarbon dioxide gas contained in the exhaust gas generated by reducingiron ore for a part or the whole of the water vapor or carbon dioxide.The composition of the exhaust gas is about 0 to 5 vol. % of watervapor, about 0 to 5 vol. % of carbon dioxide gas, about 0 to 5 vol. % ofnitrogen and about 0 to 1 vol. % of oxygen, and the temperature of themedium, low temperature exhaust gas is about 300 to 500° C. at the exitof the reducing furnace.

EXAMPLES Examples 1-4

[0094] An aqueous solution of 91 g cupric nitrate (Cu(NO₃)₂.3H₂O), 73 gzinc nitrate (Zn(NO₃)₂.6H₂O) and 368 g aluminum nitrate (Al(NO₃)₃.9H₂O)dissolved in about 2 l demineralized water and an aqueous solution ofabout 250 g sodium carbonate (Na₂CO₃) dissolved in about 2 ldemineralized water were introduced dropwise into a stainless steelcontainer containing about 5 l demineralized water kept at about 80° C.for about 2 hours, while adjusting the pH to 8.0±0.5. After theintroduction, maturing was carried out for about 1 hour with leaving asit is. While, the pH was adjusted to 8.0±0.5 by adding dropwise about 1mol/l nitric acid aqueous solution or about 1 mol/l sodium carbonateaqueous sotluion. Subsequently, produced precipitates were filtered, andwashed with demineralized water until nitrate ion was not detected inthe washed solution. The cake thus obtained was dried at 120° C. for 24hours, and sintered at 350° C. for 5 hours in air. Furthermore, thesintered matter was sieved to collect 20 to 40 mesh factions to obtainthe object catalyst.

[0095] The composition of the obtained catalyst wasCuO:ZnO:Al₂O₃=30:20:50 (weight ratio).

Example 5-8

[0096] A catalyst was prepared according to the same method as Examples1-4, except that 105 g chromium nitrate (Cr(NO₃)₂.3H₂O) was used insteadof zinc nitrate.

[0097] The composition of the obtained catalyst wasCuO:Cr₂O₃:Al₂O₃=30:20:50 (weight ratio).

[0098] Reaction Method:

[0099] A prescribed amount of the above catalyst was packed in astainless steel reaction tube having an inside diameter of 20 mm. Aprescribed amount of dimethyl ether and carbon dioxide were supplied tothe reaction tube, and the reaction was carried out at a prescribedtemperature.

[0100] The reaction products and unreacted materials obtained by theabove operations were analyzed by gas chromatography.

[0101] Reaction Conditions and Experimental Results

[0102] The reaction conditions and experimental results are shown inTables 2 and 3.${{Synthesis}\quad {gas}{\quad \quad}{yield}\quad (\%)} = {\frac{{1/6} \times ( {{{CO}\quad {producing}\quad {rate}} + {H_{2}\quad {producing}\quad {rate}}} }{{Dimethyl}\quad {ether}\quad {supply}\quad {rate}} \times 100}$${{Hydrocarbon}\quad {yield}\quad (\%)} = {\frac{\sum\lbrack {{n/2} \times {Hydrocarbon}\quad {producing}\quad {rate}} \rbrack}{{Dimethyl}\quad {ether}\quad {supply}\quad {rate}} \times 100}$

[0103] n: number of carbon atoms

[0104] All units of each rate are [mol/g-cat·h] TABLE 2 CuO—ZnO—Al₂O₃(30:20:50) Catalyst (Weight ratio) Example 1 Example 2 Example 3 Example4 Conditions Temperature (° C) 250 300 350 300 CO₂/Dimethyl Ether 1 1 12 (Molar Ratio) Space Velocity (h⁻¹) 5000 5000 5000 3000 Results ofReaction DME Conversion Rate 74.8 78.2 83.1 85.5 (%) Yield (%) SynthesisGas 74.1 76.0 79.8 85.1 Hydrocarbons 0.7 2.2 3.7 0.4 H₂/CO in SynthesisGas 0.98 0.92 0.86 0.72 (Molar Ratio)

[0105] TABLE 3 CuO—ZnO—Al₂O₃ (30:20:50) Catalyst (Weight ratio) Example5 Example 6 Example 7 Example 8 Conditions Temperature (° C) 250 300 350300 CO₂/Dimethyl Ether 1 1 1 2 (Molar Ratio) Space Velocity (h⁻¹) 50005000 5000 3000 Results of Reaction DME Conversion Rate 69.3 73.5 77.480.7 (%) Yield (%) Synthesis Gas 69.0 72.1 75.6 80.6 Hydrocarbons 0.31.4 1.8 0.1 H₂/CO in Synthesis Gas 0.99 0.95 0.91 0.89 (Molar Ratio)

Examples 9-11

[0106] An aqueous solution of 91 g cupric nitrate (Cu(NO₃)₂.3H₂O), 39 gnickel nitrate (Ni(NO₃)₂.6H₂O), 37 g zinc nitrate (Zn(NO₃)₂.6H₂O) and368 g aluminum nitrate (Al(NO₃)₃.9H₂O) dissolved in about 2 ldemineralized water and an aqueous solution of about 200 g sodiumhydroxide dissolved in about 2 l demineralized water were introduceddropwise into a stainless steel container containing about 5 ldemineralized water kept at about 60° C. for about 1 hours, whileadjusting the pH to 8.0±0.5. After the introduction, maturing wascarried out for about 1 hour with leaving as it is. While, the pH wasadjusted to 8.0±0.5 by adding dropwise about 1 mol/l nitric acid aqueoussotluion or about 1 mol/l sodium hydroxide aqueous sotluion.Subsequently, produced precipitates were filtered, and washed withdemineralized water until nitrate ion was not detected in the washedsolution. The cake thus obtained was dried at 120° C. for 24 hours, andsintered at 350° C. for 5 hours in air. Furthermore, the sintered matterwas sieved to collect 20 to 40 mesh factions to obtain the objectcatalyst.

[0107] The composition of the obtained catalyst wasCuO:NiO:ZnO:Al₂O₃=30:10:10:50 (weight ratio).

Example 12

[0108] A catalyst was prepared according to the same method as Examples9-11, except that 53 g chromium nitrate (Cr(NO₃)₂.3H₂O) was used insteadof nickel nitrate.

[0109] The composition of the obtained catalyst wasCuO:Cr₂O₃:ZnO:Al₂O₃=30:10:10:50 (weight ratio).

Example 13

[0110] A catalyst was prepared according to the same method as Examples9-11, except that 33 g manganese nitrate (Mn(NO₃)₂.6H₂O) was usedinstead of nickel nitrate.

[0111] The composition of the obtained catalyst wasCuO:MnO₂:ZnO:Al₂O₃=30:10:10:50 (weight ratio).

Example 14

[0112] A catalyst was prepared according to the same method as Examples9-11, except that 53 g chromium nitrate (Cr(NO₃)₂.3H₂O) was used insteadof zinc nitrate in Example 13.

[0113] The composition of the obtained catalyst wasCuO:Cr₂O₃:MnO₂:Al₂O₃=30:10:10:50 (weight ratio).

[0114] Reaction Method

[0115] A prescribed amount of the above catalyst was packed in astainless steel reaction tube having an inside diameter of 20 mm. Aprescribed amount of dimethyl ether and water vapor were supplied to thereaction tube, and the reaction was carried out at a prescribedtemperature.

[0116] The reaction products and unreacted materials obtained by theabove operations were analyzed by gas chromatography.

[0117] Reaction Conditions and Experimental Results

[0118] The reaction conditions and experimental results are shown inTables 4 and 5.${{Hydrogen}\quad {yield}\quad (\%)} = {\frac{\begin{matrix}{{{1/6} \times ( {{H_{2}\quad {producing}{\quad \quad}{rate}} - {2 \times {CO}\quad {producing}\quad {rate}}} )} +} \\{{1/4}\quad {CO}\quad {producing}{\quad \quad}{rate}}\end{matrix}}{{Dimethyl}\quad {ether}{\quad \quad}{supply}{\quad \quad}{rate}} \times 100}$${{Methanol}\quad {yield}\quad (\%)} = {\frac{{1/2} \times {Methanol}{\quad \quad}{producing}\quad {rate}}{{Dimethyl}\quad {ether}\quad {supply}\quad {rate}} \times 100}$${{CO}\quad {yield}\quad (\%)} = {\frac{{1/4} \times {CO}\quad {producing}\quad {rate}}{{Dimethyl}\quad {ether}\quad {supply}\quad {rate}} \times 100}$

[0119] All units of each rate are [mol/g-cat·h] TABLE 4 Example 9Example 10 Example 11 Catalyst (Weight ratio) CuO—ZnO—Al₂O₃CuO—ZnO—Al₂O₃ CuO—ZnO—Al₂O₃ (30:10:10:50) (30:10:10:50) (30:10:10:50)Conditions Temperature (° C) 200   250   300   CO₂/Dimethyl Ether 10 10  10  (Molar Ratio) Space Velocity (h⁻¹) 15000    15000    15000   Results of Reaction DME Conversion Rate 83.3  98.1  100   (%) Yield (%)Hydrogen 79.2  92.0  88.5  Methanol 2.5 3.8 6.2 Hydrocarbons 0.1 0.1 0.3CO 1.5 2.2 4.9

[0120] TABLE 5 Example 12 Example 13 Example 14 Catalyst (Weight ratio)CuO—ZnO—Al₂O₃ CuO—ZnO—Al₂O₃ CuO—ZnO—Al₂O₃ (30:10:10:50) (30:10:10:50)(30:10:10:50) Conditions Temperature (° C) 250   250   250  CO₂/Dimethyl Ether 10  10  10  (Molar Ratio) Space Velocity (h⁻¹)15000    15000    15000    Results of Reaction DME Conversion Rate 94.3 92.2  91.8  (%) Yield (%) Hydrogen 86.4  85.1  84.6  Methanol 4.3 4.13.8 Hydrocarbons 0.1 0.1 0.1 CO 3.5 2.9 3.3

Examples 15-17

[0121] An aqueous solution of 405 g iron nitrate (Fe(NO₃)₃.9H₂O), 79 gchromium nitrate (Cr(NO₃)₂.3H₂O) and 37 g aluminum nitrate(Al(NO₃)₃.9H₂O) dissolved in about 2 l demineralized water and anaqueous solution of about 180 g sodium hydroxide dissolved in about 2 ldemineralized water were introduced dropwise into a stainless steelcontainer containing about 5 l demineralized water kept at about 80° C.for about 1 hours, while adjusting the pH to 8.0±0.5. After theintroduction, maturing was carried out for about 1 hour with leaving asit is. While, the pH was adjusted to 8.0±0.5 by adding dropwise about 1mol/l nitric acid aqueous sotluion or about 1 mol/l sodium hydroxideaqueous sotluion. Subsequently, produced precipitates were filtered, andwashed with demineralized water until nitrate ion was not detected inthe washed solution. The cake thus obtained was dried at 120° C. for 24hours, and sintered at 350° C. for 5 hours in air. Furthermore, thesintered matter was sieved to collect 20 to 40 mesh factions to obtainthe object catalyst.

[0122] The composition of the obtained catalyst wasFe₂O₃:Cr₂O₃:Al₂O₃=80:15:5 (weight ratio).

Example 18-20

[0123] A catalyst was prepared according to the same method as Examples15-17, except that 55 g zinc nitrate (Zn(NO₃)₂.6H₂O was used instead ofchromium nitrate.

[0124] The composition of the obtained catalyst wasCuO:ZnO:Al₂O₃=80:15:5 (weight ratio).

[0125] Reaction Method

[0126] A prescribed amount of the above catalyst was packed in astainless steel reaction tube having an inside diameter of 20 mm. Aprescribed amount of dimethyl ether and water vapor were supplied to thereaction tube, and the reaction was carried out at a prescribedtemperature.

[0127] The reaction products and unreacted materials obtained by theabove operations were analyzed by gas chromatography.

[0128] Reaction Conditions and Experimental Results

[0129] The reaction conditions and experimental results are shown inTables 6 and 7. TABLE 6 Fe₂O₃—Cr₂O₃—Al₂O₃ (80:15:5) Catalyst (Weightratio) Example 15 Example 16 Example 17 Conditions Temperature (° C) 300350 400 CO₂/Dimethyl Ether 10 10 10 (Molar Ratio) Space Velocity (h⁻¹)25000 25000 25000 Results of Reaction DME Conversion Rate 93.7 100 100(%) Yield (%) Hydrogen 91.9 95.8 93.6 Methanol 0.1 0.1 0.2 Hydrocarbons0.2 0.9 1.9 CO 1.5 3.2 4.3

[0130] TABLE 7 Fe₂O₃—ZnO—Al₂O₃ (80:15:5) Catalyst (Weight ratio) Example18 Example 19 Example 20 Conditions Temperature (° C) 300 350 400CO₂/Dimethyl Ether 10 10 10 (Molar Ratio) Space Velocity (h⁻¹) 2500025000 25000 Results of Reaction DME Conversion Rate 89.1 100 100 (%)Yield (%) Hydrogen 87.6 94.0 92.1 Methanol 0.1 0.1 0.1 Hydrocarbons 0.11.3 1.1 CO 1.3 4.6 6.7

Examples 21-28

[0131] 49.4 g cobalt acetate (Co(NO₃)₂.6H₂O) was dissolved in about 300ml demineralized water, and furthermore, 90 g γ-alumina (“N612”, NikkiKagaku) was put in the aqueous solution, followed by evaporating todryness. The matter was dried in air at 120° C. for 24 hours, andsintered at 500° C. for 3 hours in air. Subsequently, it was treated inhydrogen current at 500° C. for 3 hours to obtain the catalyst.

[0132] The composition of the obtained catalyst was Co:Al₂O₃=10:90(weight ratio).

[0133] Reaction Method

[0134] A prescribed amount of the above catalyst was packed in astainless steel reaction tube having an inside diameter of 20 mm. Aprescribed amount of dimethyl ether and water vapor and/or carbondioxide were supplied to the reaction tube, and the reaction was carriedout at a prescribed temperature.

[0135] The reaction products and unreacted materials obtained by theabove operations were analyzed by gas chromatography.

[0136] Reaction Conditions and Experimental Results

[0137] The reaction conditions and experimental results are shown inTables 8 and 9.${{CO}_{2}\quad {yield}\quad (\%)} = {\frac{{1/2} \times {CO}_{2}\quad {producing}\quad {rate}}{{Dimethyl}\quad {ether}\quad {supply}\quad {rate}} \times 100}$

[0138] All units of each rate are (mol/g-cat·h) TABLE 8 Example ExampleExample Example 21 22 23 24 Reaction Conditions Temperature (° C) 250300 350 400 H₂O/Dimethyl Ether 4 4 4 4 (Molar Ratio) CO₂/Dimethyl Ether0 0 0 0 (Molar Ratio) Space Velocity (h⁻¹) 8000 8000 8000 8000 Resultsof Reaction DME Conversion Rate 93.8 100 100 100 (%) Yield (%) SynthesisGas 84.6 91.8 92.0 88.8 Methanol 0.3 0.3 0.5 0.9 Hydrocarbons 0.4 1.13.1 6.5 CO₂ 8.5 6.8 4.4 3.6 H₂/CO in Synthesis Gas 2.63 2.45 2.36 2.22(Molar Ratio)

[0139] TABLE 9 Example Example Example Example 25 26 27 28 ReactionConditions Temperature (° C) 300 400 500 350 H₂O/Dimethyl Ether 0 0 0 2(Molar Ratio) CO₂/Dimethyl Ether 1 1 1 0.5 (Molar Ratio) Space Velocity(h⁻¹) 5000 5000 5 000 5000 Results of Reaction DME Conversion Rate 83.7100 100 96.8 (%) Yield (%) Synthesis Gas 80.1 88.4 84.1 90.4 Methanol 00 0 0.6 Hydrocarbons 3.6 8.9 15.9 2.5 CO₂ — — — 3.3 H₂/CO in SynthesisGas 0.96 0.88 0.61 1.53 (Molar Ratio)

Examples 29, 30

[0140] 6 ml hydrochloric acid and 8.33 g palladium chloride (PdCl₂) weredissolved in about 500 ml demineralized water, and 100 g zinc oxide(guaranteed reagent, Kanto Kagaku) was put in the aqueous solution,followed by evaporating to dryness. The matter was dried in air at 120°C. for 24 hours, and further sintered in air at 500° C. for 3 hours.Subsequently, this matter was put in an aqueous solution of 10 g sodiumhydroxide dissolved in about 1,000 ml demineralized water, and treatedat 50° C. with heating for about 1 hour. Then, it was washed untilchloride ion was not detected, and dried at 120° C. for 24 hours.Furthermore, this matter was graded to 20 to 40 mesh by compressionmolding, and treated in hydrogen current at 500° C. for 3 hours toobtain the catalyst.

[0141] The composition of the obtained catalyst was Pd:ZuO=5:100 (weightratio).

Examples 31, 32

[0142] A catalyst was prepared according to the same method as Examples29, 30, except that cerium oxide (guaranteed reagent, Kanto Kagaku) wasused instead of zinc oxide.

[0143] The composition of the obtained catalyst was Pd:CeO₂=5:100(weight ratio).

Examples 33, 34

[0144] 6 ml hydrochloric acid and 8.33 g palladium chloride (PdCl₂) weredissolved in about 500 ml demineralized water, and 100 g zinc γ-alumina(“N612”, Nikki Kagaku) was put in the aqueous solution, followed byevaporating to dryness. The matter was dried in air at 120° C. for 24hours, and further sintered in air at 500° C. for 3 hours. Subsequently,this matter was put in an aqueous solution of 50 g sodium hydroxidedissolved in about 1,000 ml demineralized water, and treated at 50° C.with heating for about 1 hour. Then, it was separated without washing,and dried. Furthermore, this matter was graded to 20 to 40 mesh bycompression molding, and treated in hydrogen current at 500° C. for 3hours to obtain the catalyst.

[0145] The composition of the obtained catalyst wasPd:Na₂O:Al₂O₃=5:0.4:100 (weight ratio).

Examples 35, 36

[0146] 6 ml hydrochloric acid and 8.33 g palladium chloride (PdCl₂) weredissolved in about 500 ml demineralized water, and 100 g silica gel(“ID”, Fuji Davidson Kagaku) was put in the aqueous solution, followedby evaporating to dryness. The matter was dried in air at 120° C. for 24hours, and further sintered in air at 500° C. for 3 hours. Subsequently,this matter was put in an aqueous solution of 10 g calcium hydroxidedissolved in about 1,000 ml demineralized water, and treated at 50° C.with heating for about 1 hour. Then, it was washed, followed by drying.Furthermore, about 80 g of this matter was put in an aqueous solution of6.6 g calcium hydroxide dissolved in about 200 ml demineralized water,and evaporated to dryness, followed by drying. Furthermore, this matterwas graded to 20 to 40 mesh by compression molding, and treated inhydrogen current at 500° C. for 3 hours to obtain the catalyst.

[0147] The composition of the obtained catalyst was Pd:CaO:SiO₂=5:5:100(weight ratio).

[0148] Reaction Method

[0149] A prescribed amount of the above catalyst was packed in astainless steel reaction tube having an inside diameter of 20 mm. Aprescribed amount of dimethyl ether and water vapor and/or carbondioxide were supplied to the reaction tube, and the reaction was carriedout at a prescribed temperature.

[0150] The reaction products and unreacted materials obtained by theabove operations were analyzed by gas chromatography.

[0151] Reaction Conditions and Experimental Results

[0152] The reaction conditions and experimental results are shown inTables 10 and 11. TABLE 10 Example 29 Example 30 Example 31 Example 32Catalyst (weight ratio) Pd-ZnO (5:100) Pd-CeO₂ (5:100) ReactionConditions Temperature (° C.) 300 350 300 350 H₂O/Dimethyl Ether 5 0 5 0(Molar Ratio) CO₂/Dimethyl Ether 0 1 0 1 (Molar Ratio) Space Velocity(h⁻¹) 12000 7000 12000 7000 Results of Reaction DME Conversion Rate (%)99.7 89.4 91.4 90.2 Yield Synthesis Gas (%) Methanol 93.6 87.2 83.4 87.6Hydrocarbons CO₂ 3.1 — 4.4 — H₂/CO in Synthesis Gas 2.46 0.95 2.20 0.84(Molar Ratio)

[0153] TABLE 11 Example 33 Example 34 Example 35 Example 36Pd-Na₂O-Al₂O₃ Pd-CaO-SiO₂ Catalyst (weight ratio) (5:0.4:100) (5:5:100)Reaction Conditions Temperature (° C.) 300 350 300 350 H₂O/DimethylEther 5 0 5 0 (Molar Ratio) CO₂/Dimethyl Ether 0 1 0 1 (Molar Ratio)Space Velocity (h⁻¹) 12000 7000 12000 7000 Results of Reaction DMEConversion Rate (%) 88.9 84.9 95.1 73.8 Yield Synthesis Gas 79.5 83.786.1 72.1 (%) Methanol 0.1 0 0.1 0.1 Hydrocarbons 4.1 1.2 5.1 1.7 CO₂5.2 — 3.8 — H₂/CO in Synthesis Gas 2.38 0.88 2.51 0.89 (Molar Ratio)

Examples 21-28

[0154] 0.777 g iridium chloride (IrCl₃) was dissolved in about 300 mldemineralized water, and furthermore, 99.5 g γ-alumina (“A10-4”,Shokubai Gakkai) was put in the aqueous solution, followed byevaporating to dryness. The matter was dried in air at 120° C. for 24hours, and sintered at 500° C. for 3 hour in air. Subsequently, it wastreated in hydrogen current at 500° C. for 3 hours to obtain thecatalyst.

[0155] The composition of the obtained catalyst was Ir:Al₂O₃=0.5:99.5(weight ratio).

[0156] Reaction Method

[0157] A prescribed amount of the above catalyst was packed in astainless steel reaction tube having an inside diameter of 20 mm. Aprescribed amount of dimethyl ether and water vapor were supplied to thereaction tube, and the reaction was carried out at a prescribedtemperature.

[0158] The reaction products and unreacted materials obtained by theabove operations were analyzed by gas chromatography. ReactionConditions and Experimental Results The reaction conditions andexperimental results are shown in Tables 12 and 13. TABLE 12 Example 37Example 38 Example 39 Ir-Al₂O₃ Catalyst (weight ratio) 0.5:99.5Conditions Temperature (° C.) 350 400 450 H₂O/Dimethyl Ether 1 1 1(Molar Ratio) Space Velocity (h⁻¹) 10000 10000 10000 Results of ReactionDME Conversion Rate (%) 18.7 40.2 98.7 Yield Synthesis Gas 4.7 14.5 73.0(%) Methanol 14.0 13.7 2.9 Hydrocarbons 0 12.1 22.8 CO₂ 0 0 0

[0159] TABLE 13 Example 40 Example 41 Example 42 Ir-Al₂O₃ Catalyst(weight ratio) 0.5:99.5 Conditions Temperature (° C.) 450 450 450H₂O/Dimethyl Ether 3 5 10 (Molar Ratio) Space Velocity (h⁻¹) 10000 1000010000 DME conversion Rate (%) 98.0 97.3 99.5 Results of Reaction YieldSynthesis Gas 83.2 89.5 95.6 (%) Methanol 1.1 0.3 0.2 Hydrocarbons 13.77.5 3.7 CO₂ 0 0 0

Examples 43-48

[0160] 0.863 g platinum chloride (PtCl₄) was dissolved in about 300 ml10 wt. % hydrochloric acid aqueous solution, and furthermore, 99.5 gγ-alumina (“ALO-4”, Shokubai Gakkai) was put in the aqueous solution,followed by evaporating to dryness. The matter was dried in air at 120°C. for 24 hours, and sintered at 500° C. for 3 hour in air.Subsequently, it was treated in hydrogen current at 500° C. for 3 hoursto obtain the catalyst.

[0161] The composition of the obtained catalyst was Pt:Al₂O₃=0.5:99.5(weight ratio).

[0162] Reaction Method

[0163] A prescribed amount of the above catalyst was packed in astainless steel reaction tube having an inside diameter of 20 mm. Aprescribed amount of dimethyl ether and water vapor were supplied to thereaction tube, and the reaction was carried out at a prescribedtemperature.

[0164] The reaction products and unreacted materials obtained by theabove operations were analyzed by gas chromatography.

[0165] Reaction Conditions and Experimental Results

[0166] The reaction conditions and experimental results are shown inTables 14 and 15. TABLE 14 Example 43 Example 44 Example 45 Pt-Al₂O₃Catalyst (weight ratio) 0.5:99.5 Conditions Temperature (° C.) 300 350400 H₂O/Dimethyl Ether 1 1 1 (Molar Ratio) Space Velocity (h⁻¹) 1000010000 10000 Results of Reaction DME Conversion Rate (%) 21.6 40.2 98.0Yield Synthesis Gas 7.1 19.3 52.9 (%) Methanol 9.3 11.7 45.1Hydrocarbons 2.2 12.5 0 CO₂ 3.0 0 0

[0167] TABLE 15 Example 46 Example 47 Example 48 Pt-Al₂O₃ Catalyst(weight ratio) (0.5:99.5) Conditions Temperature (° C.) 400 400 400H₂O/Dimethyl Ether 3 5 10 (Molar Ratio) Space Velocity (h⁻) 10000 1000010000 Results of Reaction DME Conversion Rate (%) 96.6 95.9 97.6 YieldSynthesis Gas 74.1 79.4 83.6 (%) Methanol 18.7 11.4 4.3 Hydrocarbons 0 00 CO₂ 3.8 5.1 9.7

Examples 49-54

[0168] 1.40 g rhodium nitrate (Rh(NO₃)₃) was dissolved in about 300 mldemineralized water, and furthermore, 99.5 g γ-alumina (“ALO-4”,Shokubai Gakkai) was put in the aqueous solution, followed byevaporating to dryness. The matter was dried in air at 120° C. for 24hours, and sintered at 500° C. for 3 hour in air. Subsequently, it wastreated in hydrogen current at 500° C. for 3 hours to obtain thecatalyst.

[0169] The composition of the obtained catalyst was Rh:Al₂O₃=0.5:99.5(weight ratio).

[0170] Reaction Method

[0171] A prescribed amount of the above catalyst was packed in astainless steel reaction tube having an inside diameter of 20 mm. Aprescribed amount of dimethyl ether and water vapor dioxide weresupplied to the reaction tube, and the reaction was carried out at aprescribed temperature.

[0172] The reaction products and unreacted materials obtained by theabove operations were analyzed by gas chromatography.

[0173] Reaction conditions and Experimental Results

[0174] The reaction conditions and experimental results are shown inTables 16 and 17. TABLE 16 Example 49 Example 50 Example 51 Rh-Al₂O₃Catalyst (weight ratio) (0.5:99.5) Conditions Temperature (° C.) 350 400450 H₂O/Dimethyl Ether 1 1 1 (Molar Ratio) Space Velocity (h⁻¹) 1000010000 10000 Results of Reaction DME Conversion Rate (%) 19.1 65.3 89.7Yield Synthesis Gas 7.4 40.5 65.5 (%) Methanol 11.7 7.2 1.8 Hydrocarbons0 17.6 22.4 CO₂ 0 0 0

[0175] TABLE 17 Example 52 Example 53 Example 54 Rh-Al₂O₃ Catalyst(weight ratio) (0.5:99.5) Conditions Temperature (° C.) 400 400 400H₂O/Dimethyl Ether 3 5 10 (Molar Ratio) Space Velocity (h⁻) 10000 1000010000 Results of Reaction DME Conversion Rate (%) 72.1 88.6 90.9 YieldSynthesis Gas 57.0 76.5 78.7 (%) Methanol 3.1 1.3 0.5 Hydrocarbons 10.57.0 2.8 CO₂ 1.5 3.8 8.9

Examples 55-56

[0176] 0.833 g palladium chloride (PdCl₂) was dissolved in 5 mlhydrochloric acid, and the volume was made about 500 ml by addingdemineralized water. 99.5 g silica gel (“SIO-2”, Shokubai Gakkai) wasput in the aqueous solution, followed by evaporating to dryness. Thematter was dried in air at 120° C. for 24 hours, and sintered at 500° C.for 3 hours in air. Subsequently, after grading to 20 to 40 mesh, it wastreated in hydrogen current at 500° C. for 3 hours. The composition ofthis matter Pd:Al₂O₃=0.5:99.5 (weight ratio). γ-alumina (“ALO-4”,Shokubai Gakkai) graded to 20 to 40 mesh was mixed physically with thismatter at a ratio by weight of 1:1 to obtain the catalyst.

Examples 60-64

[0177] 0.833 g palladium chloride (PdCl₂) was dissolved in 5 mlhydrochloric acid, and the volume was made about 500 ml by addingdemineralized water. 98.5 g silica gel (“SIO-4”, Shokubai Gakkai) wasput in the aqueous solution, followed by evaporating to dryness. Thematter was dried in air at 120° C. for 24 hours, and sintered in air at500° C. for 3 hours. Subsequently, the matter was put in an aqueoussolution of 1.46 g potassium carbonate (K₂CO₃) dissolved in about 500 mldemineralized water, and evaporated to dryness. Then, the matter wasdried in air at 120° C. for 24 hours, and sintered in air at 500° C. for3 hours. Furthermore, after grading to 20 to 40 mesh, it was treated inhydrogen current at 500° C. for 3 hours. The composition of this matterwas Pd:K₂O:A₂O₃=0.5:1.0:98.5 (weight ratio). γ-alumina (“ALO-4”,Shokubai Gakkai) graded to 20 to 40 mesh was mixed physically with thismatter at a ratio by weight of 1:1 to obtain the catalyst.

Examples 65-69

[0178] A catalyst was prepared according to the same method as Examples55-59, except that titania (“TIO-4”, Shokubai Gakkai) was used insteadof silica gel.

[0179] Reaction Method

[0180] A prescribed amount of the above catalyst was packed in astainless steel reaction tube having an inside diameter of 20 mm. Aprescribed amount of dimethyl ether and water vapor and/or carbondioxide were supplied to the reaction tube, and the reaction was carriedout at a prescribed temperature.

[0181] The reaction products and unreacted materials obtained by theabove operations were analyzed by gas chromatography.

[0182] Reaction Conditions and Experimental Results

[0183] The reaction conditions and experimental results are shown inTables 18 and 20. TABLE 18 Example 55 Example 56 Example 57 Example 58Example 59 Catalyst Pd/SiO₂ + Al₂O₃ (weight ratio) ((0.5:99.5):100)Conditions Temperature (° C.) 350 400 450 400 400 H₂O/Dimethyl Ether 1 11 5 10 (Molar Ratio) Space Velocity 10000 10000 10000 10000 10000 (h⁻¹)Results DME Conversion Rate 40.6 81.6 95.6 93.7 97.3 of (%) ReactionYield Synthesis 22.7 48.1 40.2 81.5 76.2 (%) Gas Methanol 8.5 3.3 1.90.3 0.3 Hydrocarbons 9.3 30.2 53.5 10.7 16.4 CO₂ 0 0 0 1.2 4.4

[0184] TABLE 19 Example 60 Example 61 Example 62 Example 63 Example 64Catalyst Pd—K₂O/SiO₂ + Al₂O₃ (weight ratio) ((0.5:1.0:98.5):100)Conditions Temperature (° C.) 350 400 450 400 400 H₂O/Dimethyl Ether 1 11 5 10 (Molar Ratio) Space Velocity 10000 10000 10000 10000 10000 (h⁻¹)Results DME Conversion Rate 28.0 24.4 40.9 48.6 76.9 of (%) ReactionYield Synthesis 4.5 5.6 8.2 42.1 72.7 (%) Gas Methanol 23.5 18.1 7.8 5.52.2 Hydrocarbons 0 0.7 24.9 0.1 0.1 CO₂ 0 0 0 0.4 1.9

[0185] TABLE 20 Example 65 Example 66 Example 67 Example 68 Example 69Catalyst Pd—TiO₂ + Al₂O₃ (weight ratio) ((0.5:99.5):100) ConditionsTemperature (° C.) 350 400 450 400 400 H₂O/Dimethyl Ether 1 1 1 5 10(Molar Ratio) Space Velocity 10000 10000 10000 10000 10000 (h⁻¹) ResultsDME Conversion Rate 23.4 29.5 46.8 69.9 83.5 of (%) Reaction YieldSynthesis 11.5 17.4 15.9 60.2 76.6 (%) Gas Methanol 2.8 8.0 12.6 4.6 1.1Hydrocarbons 5.9 2.1 16.8 1.6 0.9 CO₂ 3.3 2.1 1.4 3.5 4.9

Examples 70-72

[0186] 24.8 g nickel nitrate (Ni(NO₃)₂.6H₂O) was dissolved in about 300ml demineralized water, and furthermore, 95 g γ-alumina (“ALO-4”,Shokubai Gakkai) was put in the aqueous solution, followed byevaporating to dryness. The matter was dried in air at 120° C. for 24hours, and sintered at-500° C. for 3 hour in air. Subsequently, it wastreated in hydrogen current at 500° C. for 3 hours to obtain thecatalyst.

[0187] The composition of the obtained catalyst was Ni:Al₂O₃=5:95(weight ratio).

Examples 73-75

[0188] 32.1 g nickel nitrate (Ni(NO₃)₂.6H₂O) was dissolved in about 300ml demineralized water, and furthermore, 90 g γ-alumina (“ALO-4”,Shokubai Gakkai) was put in the aqueous solution, followed byevaporating to dryness. The matter was dried in air at 120° C. for 24hours, and sintered at 500° C. for 3 hour in air. Subsequently, it wastreated in a mixed gas current of hydrogen sulfide and hydrogen at amolar ratio of 1:1 at 500° C. for 3 hours to obtain the catalyst.

[0189] The composition of the obtained catalyst was NiS:Al₂O₃=10:90(weight ratio).

[0190] Reaction Method

[0191] A prescribed amount of the above catalyst was packed in astainless steel reaction tube having an inside diameter of 20 mm. Aprescribed amount of dimethyl ether and water vapor were supplied to thereaction tube, and the reaction was carried out at a prescribedtemperature.

[0192] The reaction products and unreacted materials obtained by theabove operations were analyzed by gas chromatography.

[0193] Reaction Conditions and Experimental Results

[0194] The reaction conditions and experimental results are shown inTables 21 and 22. TABLE 21 Example 70 Example 71 Example 72 Ni-Al₂O₃Catalyst (weight ratio) (5:95) Conditions Temperature (° C.) 350 400 450H₂O/Dimethyl Ether 1 1 1 (Molar Ratio) Space Velocity (h^(−1z)) 1000010000 10000 Results of Reaction DME Conversion Rate (%) 31.4 69.7 91.0Yield Synthesis Gas 17.6 41.8 57.3 (%) Methanol 10.0 5.6 0.9Hydrocarbons 3.8 22.3 32.8 CO₂ 1.5 3.2 4.3

[0195] TABLE 22 Example 73 Example 74 Example 75 NiS-Al₂O₃ Catalyst(weight ratio) (10:90) Conditions Temperature (° C.) 350 400 450H₂O/Dimethyl Ether 1 1 1 (Molar Ratio) Space Velocity (h⁻) 10000 1000010000 Results of Reaction DME Conversion Rate (%) 36.9 71.2 93.5 YieldSynthesis Gas 27.0 65.5 90.7 (%) Methanol 9.1 4.2 0.1 Hydrocarbons 0.81.5 2.8 CO₂ 0 0 0

Example 76

[0196] Using a cathode base plate made of porous lanthanum calciummanganite La_(0.75)Ca_(0.25)MnO₃, a solid electrolyte membrane ofstabilized zirconia 8 mol % Y₂O₃—ZrO₂ was formed on the base plate, anda platinum anode was provided on the electrolyte membrane to complete asolid electrolyte-type fuel cell. The fuel cell was operated at 1,000°C., and a mixed gas of 4.7% dimethyl ether, 2.6% water vapor, theremainder Ar gas was directly supplied to be anode, and oxygen wassupplied to the cathode as the oxidizing agent gas. Both electrodes wereconnected through a galvanostat, and electricity generationcharacteristics were investigated. As a comparison, hydrogen, which isordinarilly used, was supplied to the anode instead of the mixed gas,and electricity generation characteristics thereof were alsoinvestigated.

[0197] The results are shown in FIG. 3. In the figure, ♦ is dimethylether (voltage), ▪ is hydrogen (voltage), ⋄ is dimethyl ether (generatedelectric power), and □ is hydrogen (generated electric power),respectively.

[0198] It can be seen that, even by supplying dimethyl ether and watervapor directly to the anode, electricity generation can be conducted tothe degree of no problem as a solid electrolyte-type fuel cell, althoughelectric generation efficiency is slightly inferior to the case ofhydrogen. Moreover, problems of electrode deterioration and the like didnot occur.

Example 77

[0199]FIG. 4 is a flow sheet illustrating an example of the electricitygeneration method using the dimethyl ether reformed gas of theinvention.

[0200] In a sintering machine cooler 11, sintered ore was air-cooled,the exhaust gas at 200 to 500° C. generated there was delivered to aheat exchanger 12 for heating water, a heat exchanger 13 for heating rawmaterial gas and a heat exchanger 14 for heating heating medium. Theheating medium heated by the sensible heat of the exhaust gas of thesintering machine cooler 11, is delivered to a dimethyl ether reformer15. At the apparatus, a mixed gas consisting of dimethyl ether, steamand carbon dioxide gas, which has been previously heated by thesintering machine exhaust gas, is introduced into a plurality ofreaction tubes arranged in the reformer 15. The inside of the reactiontubes is packed with dimethyl ether reforming catalyst, and bycontacting the mixed gas consisting of dimethyl ether, steam and carbondioxide gas with the catalyst, a mixed gas of carbon monoxide andhydrogen is produced. The inside temperature of the reformed 15 is, ingeneral, in the temperature range of 200 to 500° C., although it variesaccording to the type of the catalyst to be packed. The producedreformed gas contains a small amount of unreacted dimethyl ether.However, dimethyl ether itself is fuel gas having a great calorificvalue, and accordingly, the reformer gas containing dimethyl ether hasno problem as the fuel for the combustor 16 for gas turbine. Theobtained reformed gas is delivered to the combustor 16, and burns by theair for combustion supplied from a compressor 17. The exhaust gasgenerated in the combustor 16 is delivered to the gas turbine 18, androtates an electricity generator 19 to generate electricity. The gasdischarged from the gas turbine 18 is delivered to a gas turbine heatrecovering boiler 20. The steam obtained in the gas turbine heatrecovering boiler 20 is utilized as process steam in an ironmanufacturing factory (not illustrated).

Generation Examples 1-4 and Comparative Generation Example

[0201] Using the dimethyl ether reformed gas obtained in a prescribedcatalyst example, electricity generation tests were carried out by asimple open type gas turbine. TABLE 23 Generation Generation GenerationGeneration Comparative Example 1 Example 2 Example 3 Example 4Generation Condition Reformed Gas Example 2 Example 5 Example 10 Example27 Comparative Reaction Reformed Gas 337 334 329 342 320 Temp. (° C.)Exhaust Gas 570 561 547 584 530 Temp. (° C.) Results Generating 44.644.3 43.6 45.8 41.5 Efficiency (%)

[0202] TABLE 24 Comparative Reaction Catalyst (wt. ratio) CuO—ZnO—Al₂O₃(30:20:50) Conditions Temperature (° C.) 360 H₂O/Methanol 2 (MolarRatio) Space Velocity (h⁻¹) 15000 Results of Reaction MethanolConversion 84.2 Rate (%) Yield Hydrogen 73.9 (%) CO₂ 21.5 CO 4.6

Example 78

[0203]FIG. 5 is a flow sheet illustrating an example of the reducingmethod of iron ore using the dimethyl ether reformed gas of theinvention.

[0204] Dimethyl ether is previously heated at an heat exchanger 21 bythe exhaust gas at 200 to 500° C. after 20 reducing iron ore,furthermore, mixed with the exhaust gas comprising mainly steam andcarbon dioxide gas after reducing iron ore supplied by a blower 22, andthen, delivered to a dimethyl ether reformer 23. At the reformer 23,dimethyl ether reforming catalyst is packed in a plurality of reactiontubes arranged therein, and the exhaust gas after reducing iron ore isintroduced to the outside of the reaction tubes for supplying heat forendothermic reaction. By contacting the mixed gas consisting of dimethylether the exhaust gas after reducing iron ore with the catalyst in thereaction tubes, reformed gas comprising mainly carbon monoxide andhydrogen is produced. The inside temperature of the reformer 23 is, ingeneral, in the temperature range of 200 to 500° C., although it variesaccording to the type of the catalyst to be packed. The obtainedreformed gas is delivered is a heating furnace 24 to raise itstemperature to 800 to 1000° C., and introduced into a reducing furnace25. At the reducing furnace 25, iron ore is loaded from the upper part,and the iron ore is reduced by the reformed gas introduced from themiddle bottom part, and the reduced iron is discharged from the underpart.

Reduction Examples 1-6

[0205] A prescribed amount of iron ore pellets or clump ore having agrain diameter of 5 to 10 mm was loaded in a shaft-type reducingfurnace. The dimethyl ether reformed gas obtained in a prescribedcatalyst example was heated to a prescribed temperature, and aprescribed amount was streamed for a prescribed time to reduce iron ore.TABLE 25 Reduction Reduction Reduction Reduction Reduction ReductionExample 1 Example 2 Example 3 Example 4 Example 5 Example 6 Raw OrePellet Clump Pellet Pellet Pellet Pellet Material Ore Loaded Amount 1 11 1 1 1 (kg) Conditions Reformed Gas Catalyst Catalyst Catalyst CatalystCatalyst Catalyst Example 5 Example 5 Example 10 Example 27 Example 5Example 5 Reformed Gas 4 4 3 6 5 3 Flow Rate (Nm³/h) Inlet Temp. 900 900850 950 850 950 (° C.) Pressure 1 1 1 1 1 1 (atm) Time (h) 3 3 2 3 2 3Results Metallized Rate 92 92 94 93 91 91 (%)

[0206] Industrial Applicability

[0207] The catalyst of the invention can obtain hydrogen or synthesisgas in a high yield by reaction dimethyl ether and water vapor or carbondioxide at a low temperature of 150 to 600° C. The hydrogen obtained inthe invention has wide applications as various raw materials, and isuseful for fuel cell, fuel for electricity generation, reduction of ironore, etc.

1. A catalyst for producing hydrogen gas from a mixed gas comprisingdimethyl ether and water vapor or carbon dioxide gas, which comprisescopper, iron, cobalt, palladium, iridium, platinum, rhodium, or nickelas an active component.
 2. The catalyst as set forth in claim 1 wherein,the active component is copper or iron, the mixed gas comprises dimethylether and carbon dioxide gas, and the produced gas is synthetic gas. 3.The catalyst as set forth in claim 1 wherein, the active component iscobalt, palladium, iridium, platinum, rhodium or nickel, the mixed gascomprises dimethyl ether and water vapor, and the produced gas issynthesis gas.
 4. The catalyst as set forth in claim 1 wherein, theactive component is copper or iron, the mixed gas comprises dimethylether and water vapor, and the produced gas comprises hydrogen as aprincipal component.
 5. The catalyst as set forth in claim 1 wherein,the active component is cobalt or palladium carried by a metal oxidehaving basicity, and the produced gas is synthesis gas.
 6. The catalystas set forth in claim 1 wherein, the active component is platinum, themixed gas comprises dimethyl ether and water vapor, and the produced gasis synthesis gas.
 7. A method of producing hydrogen gas which comprisescontacting a mixed gas comprising dimethyl ether and water vapor orcarbon dioxide gas with a catalyst as set forth in claim
 1. 8. A methodof producing synthesis gas wherein, the mixed gas comprises dimethylether and carbon dioxide gas, and the catalyst is as set forth in claim2.
 9. A method of producing synthesis gas wherein, the mixed gascomprises dimethyl ether and water vapor, and the catalyst is as setforth in claim
 3. 10. A method of producing water vapor wherein, themixed gas comprises dimethyl ether and water vapor, and the catalyst isas set forth in claim
 4. 11. A fuel cell using dim ethyl ether as thefuel and a catalyst as set forth in claim
 1. 12. A solidelectrolyte-type fuel cell using a mixed gas comprising dimethyl etherand water vapor as fuel gas and a catalyst as set forth in claim
 1. 13.As electricity generation method using dimethyl ether reformed gas whichcomprises reforming dimethyl ether to produce synthesis gas or hydrogengas by adding water vapor or carbon dioxide gas to the dimethyl etherand catalyzing them using a catalyst as set forth in claim 1, and usingthe produced gas as a fuel for engine.
 14. The electricity generationmethod as set forth in claim 13 which comprises reforming dimethyl etherutilizing medium, low temperature waste heat in the range of 200 to 500°C.
 15. An electricity generating apparatus which comprises a reformerloaded with a catalyst as set forth in claim 1, a combustor for burningthe synthesis gas or hydrogen gas, and an electricity generator havinggas turbine rotated by the combustion exhaust gas generated in thecombustor.
 16. A method of manufacturing reduced iron which comprisesreforming dimethyl ether to produce synthesis gas or hydrogen gas byadding water vapor or carbon dioxide gas to the dimethyl ether andcatalyzing them using a catalyst as set froth in claim 1, and reducingiron are using the produced gas.
 17. The method of manufacturing reducediron as set forth in claim 16 wherein the reforming of dimethyl ether iscarried out using an exhaust gas containing water vapor and carbondioxide gas obtained by reducing the iron are.
 18. The method ofmanufacturing reduced iron as set forth in claim 16 or 17 whereinsensible heat of the exhaust gas obtained by reducing the iron are isutilized as a heating source of the dimethyl ether reforming.
 19. Amanufacturing apparatus of reduced iron which comprises a reformerloaded with a catalyst as set forth in claim 1, and a reducing furnaceloaded with iron ore, and the reducing furnace being connected with thereformer so that synthesis gas or hydrogen gas produced in the reformeris supplied to the reducing furnace.